Solar panel roof mounting system

ABSTRACT

Apparatus is provided for securing solar energy collection devices to a roof. A plurality of rails ( 103, 104 ) are provided. Each rail is attachable to a roof ( 102 ) at mutually displaced positions and defines a rail slot ( 702, 915 ). Attachment devices ( 917 ) are provided, each configured to engage with a rail slot ( 702, 915 ) such that in a first condition the devices are free to move along the slot and in the second condition the devices are secured within the slot. The attachment devices ( 917 ) include an engaging portion ( 919 ) that protrudes from the slot to engage with a solar energy collection device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from United Kingdom Patent Application No. 06 10 031.7, filed 19 May 2006, the entire disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to securing solar energy collection devices to a roof.

BACKGROUND OF THE INVENTION

Mounting systems for supporting solar energy collection devices are known, many of which are configured to place the collection devices at a particular orientation, while at the same time providing a firm anchoring.

Many known systems have been attached to buildings and on the whole the collection panels are effectively treated as part of the building, being in common ownership such that an occupant or owner may be responsible both for the solar energy collection systems and the fabric of the building itself.

Increasingly, in the future, it is likely that alternative relationships may be developed in which a separate organisation is responsible for the ownership, maintenance and operation of solar energy collection systems, without having any direct relationship with the ownership or control of the building on which the devices are situated. Consequently, under these circumstances, it is preferable for solar energy devices to be installed and maintained on a roof while at the same time minimising the actual physical impact upon the roof itself. Consequently, the roof should not be damaged and opportunities for mechanical attachment to the roof may be limited. Thus, under these circumstances, any approach which facilitates the attachment of solar collection devices to a roof while at the same time enhancing the structural integrity of the roof (as distinct from degrading the structural integrity) would be advantageous.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided an apparatus for securing solar energy collection (SEC) devices to a roof, comprising a plurality of rails, each said rail attachable to a roof at mutually displaced positions and defining a rail slot. Attachment devices are each configured to engage with a rail slot such that in a first condition the devices are free to move along the rail slot and in a second condition the devices are secured within a rail slot. The attachment devices include an engaging portion that protrudes from the slot to engage with an SEC.

In a preferred embodiment, the rail includes a cavity for receiving one or more transmission cables.

According to a second aspect of the present invention there is provided a method of installing solar energy collection devices (SECs) onto the roof of a building, comprising the step of fixing a plurality of rails to a roof at mutually displaced positions, wherein each said rail includes a rail slot. The method further comprises placing a first SEC device over at least one rail and attaching the SEC device to a first rail, using an attachment device that includes an engagement portion that engages with the rail slot of the first rail and a protruding portion that secures the first solar energy collection device.

In a preferred embodiment, the rail is located at an intersection of adjacent roof membranes and includes a securing step for securing the membranes. In a preferred embodiment, the securing step includes locating a first channel section of the rail that defines a channel onto the roof, placing the adjacent rail member over the channel and securing the membrane by forcing a second slot section of said rail into said channel.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 shows a commercial building;

FIG. 2 shows a building embodying an aspect of the present invention;

FIG. 3 shows a first stage in the installation of a solar energy collection device on to a roof;

FIG. 4 shows a mounting plate;

FIG. 5 shows how solar arrays can be attached to mounting plates;

FIG. 6 illustrates an entire solar energy collection system secured to rails on a roof;

FIG. 7 shows a first example of an embodiment of the present invention;

FIG. 8 shows a second example of an embodiment of the present invention;

FIG. 9 shows a further embodiment of the present invention incorporating a rail with a more complex cross-section;

FIG. 10 shows an example of an embodiment of the present invention suitable for retro-fitting;

FIG. 11 shows an embodiment of the present invention suitable for attachment to a corrugated metal roof; and

FIG. 12 shows an embodiment of the present invention where in a rail has been integrally formed as part of a roof panel.

DESCRIPTION OF THE BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a commercial building 101, such as a warehouse or factory unit etc. In this example, the building 101 has a modestly sloping roof 102 and it is appreciated that some commercial buildings may have a flat roof.

FIG. 2 shows the building of FIG. 1 onto which rails 103, 104, 105, 106 embodying a preferred aspect of the present invention have been attached. The rails are located at mutually displaced positions and each defines a rail slot, as illustrated subsequently. The rails are provided so as to facilitate the installation of solar energy collection devices on to the roof 102 in which a number of rails 103 to 106 etc are fixed to the roof 102 at mutually displaced positions, with each of the rails including a rail slot. A solar energy collection device is then placed over at least one of the rails and the collection device is attached to said first rail using an attachment device 917 that includes an engagement portion that engages with the rail slot and a protruding portion that secures the solar energy collection device.

In a preferred embodiment, the outer surface of the roof 102 consists of a membrane, preferably constructed from TPO material. In a first embodiment, rails 103 to 106 have been retrofitted to an existing polymer roof and specific examples of this embodiment are shown in FIG. 7, FIG. 8 and FIG. 10. In an alternative embodiment, the rails are applied before the polymer roof and may be used to assist in the attachment of the polymer roof, as shown in FIG. 9. In an alternative embodiment, the outer surface of roof 102 is of a corrugated metal construction and the rails 103 to 106 are applied to this corrugated construction as illustrated in FIG. 11. Alternatively, as illustrated in FIG. 12, the corrugated roof sections may be formed in such a way as to have the rails pre-configured.

FIG. 3 illustrates a first stage in the installation of a solar energy collection device onto roof 102. Rails 103 and 104 are shown, being part of the fabric of the roof or having been retrofitted. Wedge-shaped devices 301 and 302 have been positioned on the roof in an appropriate north-south orientation. In this preferred embodiment, the total weight of the wedge-shaped devices is adjusted so as to apply an appropriate loading to the roof 102.

FIG. 4 shows a mounting plate 401 which is supported by the support devices 301 and 302. The mounting plate 401 includes a front face 402 and a support web 403. The angle between the front face 402 and the support web 403 reflects that defined by the wedge-shaped supports themselves and is thereby held firmly by the wedge-shaped supports. It is appreciated that mechanical fastening may also be required (e.g. self-drilling screws). The support web 403 includes a channel 404 to facilitate the housing of interconnection cables.

The front face 402 is provided with a lip 405 to facilitate the attachment of the solar collection assembly to the roof 102. Web 403 may also be provided with a similar lip, either orientated outwards away from the support (301) or inwards under the support (301). In a preferred embodiment, the assembly shown in FIG. 4 is attached to a rail, such as rail 103 by an attachment device 917 that acts upon the lip 405.

It should also be appreciated that the angled formation of the panels 401 enables them to be stacked together in a nested formation to facilitate transportation to an installation site.

In a preferred embodiment and as shown in FIG. 2, the rails 103 to 106 etc run the full width of the roof so as to provide many potential fixing locations. Consequently, the configuration facilitates arranging the panels at any appropriate angle (preferably in the north-south orientation) irrespective of the actual orientation of the roof itself.

FIG. 5 shows how, in a preferred embodiment, solar arrays are attached to the front face of the mounting plates 401. This may occur onsite or in the factory during manufacture. A range of photovoltaic systems could be deployed, such as photovoltaic modules 501, crystalline laminates 502 or thin film amorphous laminates 503.

Modular installation of the support devices with mounting plates attached thereto allows an entire system, as illustrated in FIG. 6, to be established without the use of heavy lifting equipment. It is envisaged that in a preferred embodiment, the whole system could be configured by two installers, preferably followed by an electrician to complete the electrical installation.

Mechanical mounting plates are configured as illustrated in FIG. 6, with appropriate photovoltaic systems provided pre-fitted or deployed on site as appropriate, as illustrated in FIG. 5. Upon completion of the mechanical installation, an electrician would interconnect the energy collection devices and deploy additional electronic equipment.

Preferably, a transmission cable 601 is received from the array as a whole and returned to the interior of the building via an appropriate interconnection box 602 so as to allow the generated electricity to be used within the building. In a preferred embodiment, the electricity generated from the array is supplied as a dual supply together with mains power received from the grid system. Alternatively, the generated electricity may be supplied to a grid system.

In order to supply electricity to connection box 602, the individual panels must be connected together. In an embodiment, it is possible for the wedge-shaped devices to receive transmission cable and for them to be interconnected. However, in a preferred embodiment transmission cables interconnecting rows of solar collection devices are housed within some or all of the rails, such as rails 103, 104, 105 and 106.

FIG. 7 shows a first example of an apparatus for securing solar energy collection devices to a roof. An extruded rail, such as rail 103 has a cross-section 701 that defines a rail slot 702. An attachment device 917 is configured to engage with the rail slot such that in a first condition the attachment devices are free to move along the slot and in a second condition the devices are secured within the slot. The engagement devices include an engaging portion that protrudes from the slot to engage with an array of collection devices. Thus, in a preferred embodiment, an attachment device is received within slot 702 and the engaging portion engages with lip 405. The attachment device is held by slot 702 because the slot includes a re-entrant portion 703, thereby securing a cam-like device that has been twisted after insertion or for securing a bolt-like device applied to the slot from an open end. A membrane skirt 704 is shown, which is a method of welding/adhering the rail to the roof covering 102.

FIG. 8 shows an alternative embodiment in which a rail 801 is provided with an adhesive foot 802. The adhesive foot 802 facilitates attachment to the roof 102 by the application of pressure, as illustrated by arrow 803. In a preferred embodiment, the adhesive foot is provided with a tear strip, removed prior to application.

FIG. 10 illustrates a rail 901 having a more complex cross-section. In the embodiments of FIG. 7 and FIG. 8, the rail has been located over the roof membrane and is attached to the roof membrane without damaging the membrane itself. However, in an alternative configuration and to achieve a more secure fixing, the rail is located over a membrane and is attached to the roof through the membrane. The apparatus of FIG. 10 facilitates an attachment of this type. In the embodiment of FIG. 10, the rail is defined by a first channel section 901 and a second slot section 902. In this way, it is possible for a membrane 1001 to be secured between the first section 901 and the second section 902.

FIG. 10 shows how the rail assembly, consisting of the channel section 901 and a slot section 902, may be deployed when retro-fitted to an existing membrane-covered roof. The channel section 901 is fixed in position with self drilling screw 921, thereby penetrating the surface of the roof 102. An overlapping strip 1001 of waterproof membrane is laid over the channel and held in position by the slot section 902. Edges of the overlaid membrane 1001 are secured by welds 1002 or by the application of adhesive.

In the embodiment of FIG. 9, an internal roof surface is fabricated from corrugated metal 904. Metal 904 is then covered with an insulating layer 905 and the membrane 903 is rolled over the insulating layer 905, usually down the sloping roof in the direction of rails 103 to 106 as shown in FIG. 2.

In this preferred embodiment, the positions of rails 103 to 106 represent roll widths such that a rail is provided at the position of each intersection. The channel section 901 includes a first side wall 906 and a second side wall 907. An edge of a first membrane 903 is placed over the first side wall 906 and a similar edge of a second membrane 908 is placed over the second side wall 907.

Slot section 902 is provided with a first external wing 909 and a second external wing 910. After the membranes 903 and 908 have been located in position, the membranes are secured in position by the slot section 902. The slot section 902 is located in position above the channel section 901. Pressure is then applied, possibly by means of a rubber mallet so as to force external wings 909 and 910 over their respective side walls 906, 907 thereby securing the membrane edges 903, 908 and providing a weather-tight seal by an interference fit. The two membranes may be welded before fitting slot section 902 to ensure a weather-tight seal.

Slot section 902 includes a slot 915 for receiving attachment devices such as 917, including a re-entrant portion 916 for securing the attachment device.

In FIG. 9, an example of an attachment device 917 is shown. The attachment device 917 includes a cam-like portion 918 that is insertable into the rail slot 915 from above and thereafter is twistable to a locked position so as to be secured by the re-entrant portion 916.

Attachment device 917 also has an engaging portion 919 that protrudes from rail slot 915 to engage with an energy collection device, in this example by acting upon lip 405. Depending upon the desired configuration, attachment devices such as 917 may act upon lips such as 405 on the front face of a mounting plate 401 or may act upon lips on the web 403 of a mounting plate. In addition, one or more attachment devices such as 917 may be used for any given mounting plate such as 401.

An alternative example of an attachment means comprises a bolt having a head and a thread each sized such that the head is slidable in the rail slot from an open end to a specified fixing position. A further device is then attached to the thread in order to act upon lip 405.

Preferably, the slot section 902 is formed from a resilient material, such as a moulded plastic or from metal to facilitate its engagement with the channel section 901. A channel section 901 is preferably retained by a self drilling screw (TEK screw) 921.

It is appreciated that with the additional clamping force provided by a continuous rail compared to discrete fixings the total number of fixings required to overcome wind uplift forces on the membrane are reduced.

FIG. 11 shows an alternative embodiment in which the outer roof surface 102 takes the form of a corrugated metal panel 1101. In this embodiment, a rail 1102 is attached to an upper corrugation 1103 of the profiled roof panel 1101, using, for example, self drilling screws and sealed with butyl tape 1104.

FIG. 12 illustrates an alternative embodiment in which a rail 1201 has been integrally formed with the profile of a roof panel 1202. In this embodiment, a re-entrant slot 1203 is formed at the peak of the corrugation. In such an arrangement, additional openings 1204 may be provided to assist with the enclosure of transmission cables. 

1. Apparatus for securing solar energy collection devices to a roof, comprising: a plurality of rails, each said rail attachable to a roof at mutually displaced positions and defining a rail slot; attachment devices each configured to engage with a rail slot, such that in a first condition said devices are free to move along said slot and in a second condition said devices are secured within said slot; and said attachment devices include an engaging portion that protrudes from said slot to engage with a solar energy collection device.
 2. Apparatus according to claim 1, wherein said rail includes a cavity for receiving one or more transmission cables.
 3. Apparatus according to claim 1, wherein an attachment device comprises a bolt having a head and a thread each sized such that said head is slidable in the rail slot from an open end to a specified fixing position.
 4. Apparatus according to claim 1, wherein an attachment device includes a cam-like portion that is insertable into a selected rail slot from above and thereafter is twistable to a locked position in said selected rail slot.
 5. Apparatus according to claim 1, wherein said rail is located over a roof membrane and is attached to the roof through said membrane so as to secure the membrane in addition to securing the rail.
 6. Apparatus according to claim 5, wherein said rail is located at an intersection of adjacent roof membranes and includes a mechanism for securing and sealing said membranes.
 7. Apparatus according to claim 6, wherein said rail is defined by a first channel section and a second slot section, such that the membranes are secured and sealed between said first section and said second section.
 8. Apparatus according to claim 1, wherein said mounting rail is integrally formed with a roof panel.
 9. On a roof of a building, apparatus for collecting solar energy, comprising: a plurality of solar energy collection devices; a plurality of rails attached to said roof at mutually displaced positions and each defining a rail slot; attachment devices each including an engaging portion that engages with a selected rail slot and a protruding portion that secures solar collection devices.
 10. Apparatus according to claim 9, wherein said rail includes a cavity cavity for receiving one or more transmission cables or for receiving pipes or hoses conveying a heated liquid.
 11. Apparatus according to claim 9, wherein an attachment device comprises a bolt having a head and a thread each sized such that said head is slidable in the rail slot from an open end to a specified fixing position.
 12. Apparatus according to claim 9, wherein an attachment device includes a cam-like portion that is insertable into a selected rail slot from above and thereafter is twistable to a locked position in said selected rail slot.
 13. Apparatus according to claim 9, wherein said rail is located over a roof membrane and is attached to the roof through said membrane so as to secure the membrane in addition to securing the rail.
 14. Apparatus according to claim 13, wherein said rail is located at an intersection of adjacent roof membranes and includes a mechanism for securing and sealing said membranes.
 15. Apparatus according to claim 14, wherein said rail is defined by a first channel section and a second slot section, such that the membranes are secured and sealed between said first section and said second section.
 16. Apparatus according to claim 9, wherein said mounting rail is integrally formed with a roof panel.
 17. A method of installing solar energy collection devices onto a roof of a building, comprising the steps of: fixing a plurality of rails to a roof at mutually displaced positions, wherein each said rail includes a rail slot; placing a first solar energy collection device over at least one of said rails; and attaching said solar energy collection device to a first rail using an attachment device that includes an engagement portion that engages with the rail slot of said first rail and a protruding portion that secures said first solar energy collection device.
 18. A method according to claim 17, wherein said fixing step includes locating the rail over a roof membrane and attaching the rail to the roof through the membrane so as to secure the membrane to the roof in addition to securing the rail.
 19. A method according to claim 17, wherein the rail is located at an intersection of adjacent roof membranes and includes a securing and sealing step for securing and sealing said membranes.
 20. A method according to claim 19, wherein said securing step comprises the steps of: locating a first channel section of the rail that defines a channel onto the roof; placing said adjacent roof membranes over said channel; and securing said membranes by forcing a second slot section of said rail into said channel.
 21. A method according to claim 17, wherein said attachment device is a bolt (with a head and a thread) and said attaching step includes sliding said bolt along a rail with the head of said bolt secured by said rail slot.
 22. A method according to claim 17, wherein said attachment device includes a cam-like portion and said attaching step includes inserting said cam-like portion into said rail slot and twisting the attachment device.
 23. A method according to claim 17, wherein a rail includes a longitudinal cavity, including the step of inserting transmission cables or pipes/hoses through said longitudinal cavity. 